Tri Mountain Estates Dam

Tr-Mason Creek· Clark, Washington· Built 1953· Earth·
High Hazard Irrigation Recreation Private

Key Takeaway

Tri Mountain Estates Dam is classified as high hazard in Washington. It was completed in 1953 and is 73 years old. Its primary use is irrigation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Length1,355 ft
Dam TypeEarth
Max Storage177 acre-ft
Normal Storage137 acre-ft
Surface Area18 acres
Drainage Area0 sq mi
Max Discharge125 cfs
Year Completed1953 (73 years old)
NID IDWA00103

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes
Last Inspection: March 9, 2024
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

Tri-Mountain Estates LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Tri Mountain Estates Dam?

Tri Mountain Estates Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Tri Mountain Estates Dam?

Tri Mountain Estates Dam is owned by Tri-Mountain Estates LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Tri Mountain Estates Dam built?

Tri Mountain Estates Dam was completed in 1953, making it 73 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Tri Mountain Estates Dam?

Tri Mountain Estates Dam serves the following purposes: Irrigation, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Tri Mountain Estates Dam last inspected?

Tri Mountain Estates Dam was last inspected on March 9, 2024. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.